Oil burner nozzle



July I5, 1941. A. MAccl-n oIL BURNER NQzzLE Filed' Feb 24, 1940 Inventor. Aldo Mach;

His Attovfney.

e fPatented 1S, 1941 on. yimmuni NozzLn Aldo' Macchi, Belleville, N. J., assigner to General Electric Company, a corporation of New York Application February 24, 1940. serial No. 320,558 s claims. (ci. 29e- 140) This invention vrelates to oil burner nozzles, particularly of the general type disclosed in my Patent 2,022,513, granted November 26, 1935, wherein air under pressure is mixed and discharged with the oil at the nozzle tip to -eiect atomization thereof.

The object of the present invention is to produce uniform and effective atomization of the oil by means of an improved nozzle structure capable of operating at relatively low air and oil pressures.

--A particular object is to enable the rate of oil discharge from the nozzle tip to be accurately pre,- determined and also varied by means of a readily replaceable calibrated oil ow orifice embodied in thebimprovedatomizing nozzle structure.

A further object is to provide an improved air pressure oil atomizing nozzle structure having a junction or connection block provided with socket means at one end thereofjfor removably mounting an oil and air mixing nozzle tip and provided with separate oil and air pipe sockets at the other end with internal passages extendapplication, Serial No. 320;.557 led concurrently herewith. Brieily, vthe improved burner unit comprises a vbase l with adjustable'legs ll Kupon which base are mounted all of'the Principal operating and control parts of the burner unit,

including the electric motor driven blower and oil and air pumping mechanism I2, the high voltage electric ignition transformer I3, as well as the burner combustion air supply nozzle structure -ll which is adapted to be sealed into the refractory wall I5 of a boiler furnace or other type of furnace to which the conversion oil burner unit is applied. The removable jacket or cover I6 serves to enclose allof the operating parts of the burner except the nozzle..

blower i1 into the interior of the combustion air nozzle Il. 1

The motor driven mechanism I2 constitutes the electric 'motor driven oil and air pressure supply means for the improved oil atomizing nozzle ing` therefrom and joined together to form an initial oil and air mixing chamber inside thev block `and with the block also provided with a special inverted well having a Vmetering plug mounted ltherein. with a thinwalled sharp edged p orice disposed in the oil supply passage directly adjacent the mixing chamber for controlling the initial mixture of the oil with the air.

Other objects are to promote intimate and thorough mixture of the oil and air under pressure by means of a double mixing action within the nozzle body before the discharge thereof and to enable .the angle of the discharge atomized oil stream to be varied upon variation of the atomizing-air pressure. v

Other objects will appear in the following description of the accompanying drawing illustrating preferred embodiments of the invention and in which Fig. 1 is a side view partially in section :oi an automatic electrically operated conversion oil burner unit provided with the improved atomizing nozzle of the present invention; Fig. 2

. is an enlarged sectional view showing the internal Fig. 1 isshown as of the improved type more fully described .and claimed in my `copending of the present invention, the. structural details of which are more clearly shown in the enlarged views of Figs. 2 and 3. Preferably the motor driven mechanism i2 is of the improved type described and claimed in the Lum Patent 2,032,291,

granted February 25, l1936, v although any other suitable type ofmotor driven blower and oil and air :pumping means maybe provided for supply-v ing the improved atomizing nozzle 20 with oil and air under pressure through the oil supply pipe 2|' and the air supply pipe 22. Y l

Preferably the improved atomizing nozzle 20 of the present invention is mounted inside of the cooling a'ir iiow tube 24 so as to discharge substantially horizontally a stream of atomized oil along the axis of the combustion air nozzle I4 and adjacent the discharge end thereof. atomized stream of. oil prefer-ahy is ignited by electric arc produced between a pair of electrodes 2l located above and closely adjacent the end of the oil atomizing nomic-20.

As shown in the emerged sectional view of. Fis.

2, the improved structure of the atomizing nozzle 2l comprises the nozzle body or junction block 130 preferably of external hexagonal form and provided at vone end with the enlarged openings o'r boiecdl and 32 one above the other to form sockets into which are sealed respectively the oil supply pipe 2| and the air supply pipe 2,2, as by silver soldering, brazing, or the like. The nozzle body Il thus constitutes a junction or connection block for the oil and lair pipes 2| and 22 and is also provided with 'the 'interconnectedinternal oil passageways 3ia, 3 lb, llc, andthe internal Combustion air l under pressureA is supplied from the motor driven air passageways or bores 32a and 32h in order to mix the oil and air supplied from pipes 2l and` 22 together under pressure and then permit the oil and air mixture tofiow to the atomizing orifice of the nozzle through the interconnecting axial passage 33.

'I'he oil passage 3|c isformed by a bore extending axially through the removable annular metering plug 36 which is screw-threaded into the enlarged vertical opening or bore 31 which extends upwardly into the nozzle body 30 to form an inverted well or socket for the metering' plug 36. The removable metering plug 36 carries secured to the chamfered upper end thereof the calibrated oil iiow thinmetering disc 38 with the sharp edged thin walled oil now control orifice 36 formed in the center thereof in alinement with the axis of the oil passage 3 |c. In this way the upwardly directed thin walled sharp edged oil flow control orifice 38 is removably embedded within the connection block 30 directly adjacent to the junction of the separate oil and air supply passages so as to vcontrol most eectively the initial intermixing of the oil and air under pressure. The removable plug 316 is provided with suitable shoulders 4| for receiving. a special wrench so that the orifice disc 33 may be tightly seated against the upper end of the threaded vertical opening 31. v

The readily removable sealing plug 42 is screwed into the bottom. entrance of the threadaai-tasasto note that by removing the sealing plug 42 and substituting different internal plugs 36 carrying different sized oil meteringv orinces 39, the rate of oil discharged from the improved nozzle structure may be quite accurately predetermined and also readily -varied as desired. In this way the burner heat output may be readily varied between wide limits.

The end of the nozzle body or junction block opposite the oil and 'air inlet pipes 2| and 22 4is provided with an externally threaded annular boss 45 for receiving the internally threaded nozzle tip clamping nut 46 with a compression washer 41 for sealing the clamping nut 46 to the nozzle body or block 30. The clamping nut 46 carries the atomizing nozzle orifice tip 50 preferably brazed or welded thereto in cooperating relation with the inner nozzle tip plug 5| which is biased by the spring 52 into firm engagement with the inner face of the discharge orifice tip 53.

The special shape of the inner nozzle tip plug 5| is more clearly illustrated in the perspective view of Fig. 3. The small cone portion V53 extending from the face 54 of the plug 5| is adapted to fit in nesting relation within the complementary internal conical depression 55 formed centrally in coaxial relation in the. atomizing orifice tip 50 with the tip of the cone 53 in registering spaced apart relation with the restricted atomizing discharge orifice 56 located at the apex of the conical depression 55.

ed opening or inverted well 31 preferably with f a lcompression washer 43 between the head of the plug 42 and the bottom of the nozzle body or connection block 30 'so as to close the threaded opening31and form the passageway 3Ib between the top surface of the plug 42 and the bottom surface of the plug 36. Preferably sealing plug 42 is provided with a sediment well 42a as shown to protect orifice 3l.

In the form of nozzle shown in Fig. 2, the oil passage 3|ic is in opposing vertical alinement with the air passage 32h so that the oil stream issuing from the sharp-edged oil metering orifice 33 will be projected directly upward into the downwardly moving air stream in the passage 32h. This results in an oil geyser-like action that produces an initial intimate and thorough mixture of the oil and air under pressure in the vertical passage 32 with the mixing action continuing in the passages 33 and 45a. In case there are any small air bubbles or vapors in the oil supply coming through pipe 2 I, these air .bubbles or vapors will readily pass through the upwardly directed metering orince 33 `along with the oil and without separating ,from the oil, thereby preventing air pockets which might cause an appreciable discontinuity of the oil flow.

' It is important to. note that the flow of oil under pressure through the oil supply pipe 2| and the sharp edge thin disc metering oriflce 39 provides a viscosity compensated oil flow control of the improved type described and claimed in the Lum Patent 2,072,761, granted March 2, 1937. Thus in -accordance with the viscosity compensating iiow control principles set forth in 'Ihe tubular extension 53v fromthe nozzle tip I plug 5| forms a. close sliding t within the cylinthe oil and air mixture flowl passage 33 and in communication therewith. Thus the improved nozzle junction or connection block 30 is provided not only with the sockets for sealing the separate oil and air pressure supply pipes at one end thereof and with the separate inverted well or socket for removably-embedding the oil metering plugs 36 with its upwardly directed thin walled sharp edged metering orifice 38 directly at the junction of the oil and air pressure supply passages but also with a nozzle tip socket for removably mounting therein the oil and air mixing tip parts.

In operation the oil and air mixture flows under pressure from the mixing passage 33 into the largeopening 45a and further mixes in and charge the oil and air mixture in separate diagonal streams into the annular mixing chamber formed between theconical depression 55 and l the opposing cone 53, thus serving to impart a said Lum patent,A the improved nozzle structure of the present invention is capable of maintaining a practically constant oil rate .in the oil ers of the domestic type. It is also ,important rapid and turbulent rotary motion to the oil and air mixture around the cone 53. As a result the oil and air are given a further violent intermixingunder pressure before the discharge of the mixture through the restricted atomizing orifice 56 occurs.

'I'he double oil and air mixing action obtained by means of the improved atomizing nozzle structure produces in operation a very intimate and thorough intermixture of the oil and air under pressure with a uniform and effective atomiza- 2,249,482 uon or the ou resulting from the rapid expansion of the air particles upon the discharge of the mixture through the restricted orifice Il. Furthermore, the rapid rotary motion imparted to the air and oil mixture lust prior to discharge produces a relatively wide angle stream of atom-v ized oil when Athe oil and air are supplied to the atomizing nozzle at relatively low pressure. This enables the combustion air dischargingfrom the air nozzle Il to intimately intermlx with the wide angle stream of atomized oiiso as to produce a stable dame with relativelyuniform and eilicient combustionof the oil. Preferably the angle of the combustion air stream discharged -i'rom Ythe air nozzle Il is lalways maintained slightly greater than that of the stream of atomized oil in order to provide some excess of air at the boundary of the atomized oil stream and thereby insure as complete combustion of the oil as possible.

Preferably the external surface of the nozzle body or junction block 3l is formed hexagonal Letters Patent of the United States' is:

1. In an atomizing nozzle for oil burners, in

combination, a body having separate oil and air inlet passages formed therein with said passages joined together inside said body to form an oil and air mixing chamber in saidbody, and a pair of. cooperatingA orifice elements removably clamped to said body in spring biased engage` the apex of the said conical portion thereof.

2. In an oil and air'mixing nolzle for oil burners', in combination, a nozzle tip 'having an orifice so as to allow proper seating of the sealing gasket 43 on one of the dat outer faces thereof when the sealing nut I2 is screwed into the opening 31. Also the nozzle tip clamping nut 4I preferably is provided with a hexagonally formed portion lia inorder to facilitate the ready assembly and disassembly of the nozzle parts by means of ordinary wrenches.

In the modiiied form of atomizing nozzle structure embodying the improvement of the present formed therein for discharging the oil and air mixture, a nozzle body removably connected with said nozzle' tip-'and .having a passage for air under pressure formed therein in communication opening communicating with said air p :u with an-oll inlet passage formed in said body in communication with said enlarged opening. a removable plug mounted in said enlarged openwith said orifice and provided with an `enlargea'i ing and provided with a thin Walled Sharp edged metering'orificefor regulating the iiow of liquid oil from said oil inlet e to said air passage invention as shown in Fig. 4, the oil andair supply pipes 2l, 22 are sealed in socket form somewhat closer together in the nozzle body or Junction block 30 and the oil metering orifice 39 is located so as to discharge directly upwardly into the air passage 32a. The inner plug 36 carrying the oil metering disc 3B is oi' slightly modified form so as to receive an internal socket wrench for seating and removing the plug 38 from the orifice plug opening 31 in the nozzlefnody. Also the external sealing plug I2 is of slightly modified form so as to be mounted in al machined recess formed in the bottom of the nozzle body or junction block 3B.

The initial oil and air mixture formed by the upward discharge of oil through the orifice 39 Vinto the air passage 32a is further mixed in the downwardly inclined passage 33a and inpasnozzle all of which are only slightly modliied through said enlarged opening, and' a second removable plug mounted in said enlarged opening in spaced apart relation with said iirst plug for sealing said enlarged opening.

-3. In an atomizing nozzle for oil burners. in combination a nomle tip having a discharge ori- (lice and oil and air mixing means adjacent said orice, a connection block having means at one end thereof for removably mounting said nomle tlp.'said block having separate oil and air pressure supply pipe sockets formed at the other end thereof and an air pressure supply passage communicating between said air pipe socket and said nozzle tip-orifice means, said block having a well formed in a side thereof with the end of the welladjacent to and communicating with said air pressure supply passageland having a passage communicating between the side of said well and said oil pipe socket, an annular plug vremovably seated within said well and provided with a thin walled sharp edged orifice at the from the form thereof previously described. It

tween the conical depression and the cone 53 is obtained in the manner` previously described.

In order to localize any dripping of oil which mayY accumulate on the outer surface of the nozzle clamping nut G6, a twisted wire O0 prefer'- ably isdisposed in a suitable groove formed on' the exterior of the nutso that the oil may 'drip from the twisted ends of the wire il through a suitable small opening formed in the bottom end of said well for controlling the initial mixing .of the oil with the air, and a sealing plug rev 55` movably mounted in the mouth of said well.

4. An atomizing nozzle for burners including an air and oil mixing nozzle tip, a connection' block therefor having means for removably of cooling airAtube-l. This will prevent any 't accumulation of carbonized oil that might inter- 24 around the nozzle 20.

mounting said nozzle tip with the axis of the tip substantially horizontal and having separate substantially horizontal oil and air pressure inlet passages with said oil inlet passage disposed be#- low the level of .said air inlet passagevand having an inverted well extending upwardly from the bottom side of said blockand joining-said oil.

inlet passage with said air inlet passage to form an initial oil and air mixing chamber. a thin walled sharp edged4 metering orifice element, means for'mounting said element at thel upper end of said inverted well adjacent said air inlet passage for projectingastream of oil upwardly into said air passage. and removable means for sealing the mouth of said well.

5. An oil atomizing` nozzle for burners including a nozzle tip having a restricted orifice for -What I claim as new and desire to secure by I discharging a mixture of oil and air under pressure. a nozzle tip plug removably mounted in said nozzle tip and provided with a central oil and air mixing chamber with a plurality of separate passages communicating between said mixing chamber and said oriiice with said plurality of separate passages Joined together adjacent 'said orifice to form a final oil and air mixing chamber, a connection block having means for removably mounting said nozzle tip and plug at one end thereof, said block having separate oil and air pressure supply pipe sockets at the other end thereof and provided with an air pressure supply passage communicating between said air pipe socket and said*y central chamber in said nozzle plug, said block having a well formed in the side thereof with a passage connecting the side of said weil with said oil pipe socket and with the end of said well adjacent to and communicating; with said air pressure supply -passage to mix`oii with the air, a thin walled sharp edged metering orifice element having means for removably mounting said element in said well adjacent said air passage for projecting a stream of oil into said air passage, and a removable cover 4for sealing said well.

6. An air pressure oil atomizingv nozzle for burners including .an oil and air mixing nozzle tip, a connection block therefor having means for removably mounting said nozzle tip thereon and havingseparate oil and air pressure inlet passages and an initial oil/and air mixing chamber formed therein with said chamber communicating between said nozzle tip and said air inlet passage and having a weil open to the exterior of said block and communicatingv between said oil inlet passage and said mixing chamber, a thin 

